Engine components, such as crankshafts and camshafts, must be manufactured with precise dimensions. Thus, precision gauging systems are required to measure features of the devices. A number of precision coordinate gauging systems are available for the measurement of such engine components. For example, tactile sensing devices are often utilized to make the required measurements of the camshaft, for example.
Typically, the measurement involving tactile sensing devices includes the use of a follower probe that travels along an axis perpendicular to the axis of rotation of the camshaft being measured to measure features, such as roundness, diameter, and camshaft profile. An exemplary camshaft measurement gauge 10 for making such profile measurements along the axis perpendicular to a camshaft C is illustrated in FIG. 1.
The camshaft measurement gauge 10 includes a rotatable stage 12 configured to receive and rotate the camshaft C about a rotational axis A. A carrier 14 is translatable along the axis A of the camshaft C as installed on the rotatable stage 12. The camshaft measurement gauge 10 includes a radial measuring probe 16 that extends from the carrier 14 and contacts the camshaft C with a constant force to provide a tactile profile measurement perpendicular to the axis A of the camshaft C. The probe 16, however, is limited to measuring the profile of the camshaft C along the axis perpendicular to the camshaft C. Specifically, the probe 16 of the camshaft measurement gauge 10 shown in FIG. 1 does not allow for measurement of a sidewall of the camshaft C.
Federally mandated increases in fuel efficiency have pushed auto makers to develop engines that balance fuel economy and performance. In particular, multiple design variants for variable valve timing have been developed and utilized to increase fuel efficiency by varying valve lift, timing, and duration. These variations in design to meet these federal mandates have resulted in a need to accurately measure the axial profile (i.e., the change in position on-axis radially about the shaft) of camshaft groove side walls.